using System;
using System.Collections;

using Org.BouncyCastle.Asn1;

namespace Org.BouncyCastle.Asn1.X509
{
	/**
	 * PKIX RFC-2459
	 *
	 * The X.509 v2 CRL syntax is as follows.  For signature calculation,
	 * the data that is to be signed is ASN.1 Der encoded.
	 *
	 * <pre>
	 * CertificateList  ::=  Sequence  {
	 *      tbsCertList          TbsCertList,
	 *      signatureAlgorithm   AlgorithmIdentifier,
	 *      signatureValue       BIT STRING  }
	 * </pre>
	 */
	public class CertificateList
		: Asn1Encodable
	{
		private readonly TbsCertificateList	tbsCertList;
		private readonly AlgorithmIdentifier sigAlgID;
		private readonly DerBitString sig;

		public static CertificateList GetInstance(
			Asn1TaggedObject	obj,
			bool				explicitly)
		{
			return GetInstance(Asn1Sequence.GetInstance(obj, explicitly));
		}

		public static CertificateList GetInstance(
			object obj)
		{
			if (obj is CertificateList)
				return (CertificateList) obj;

			if (obj != null)
				return new CertificateList(Asn1Sequence.GetInstance(obj));

			return null;
		}

		private CertificateList(
			Asn1Sequence seq)
		{
			if (seq.Count != 3)
				throw new ArgumentException("sequence wrong size for CertificateList", "seq");

			tbsCertList = TbsCertificateList.GetInstance(seq[0]);
			sigAlgID = AlgorithmIdentifier.GetInstance(seq[1]);
			sig = DerBitString.GetInstance(seq[2]);
		}

		public TbsCertificateList TbsCertList
		{
			get { return tbsCertList; }
		}

		public CrlEntry[] GetRevokedCertificates()
		{
			return tbsCertList.GetRevokedCertificates();
		}

		public IEnumerable GetRevokedCertificateEnumeration()
		{
			return tbsCertList.GetRevokedCertificateEnumeration();
		}

		public AlgorithmIdentifier SignatureAlgorithm
		{
			get { return sigAlgID; }
		}

		public DerBitString Signature
		{
			get { return sig; }
		}

		public int Version
		{
			get { return tbsCertList.Version; }
		}

		public X509Name Issuer
		{
			get { return tbsCertList.Issuer; }
		}

		public Time ThisUpdate
		{
			get { return tbsCertList.ThisUpdate; }
		}

		public Time NextUpdate
		{
			get { return tbsCertList.NextUpdate; }
		}

		public override Asn1Object ToAsn1Object()
		{
			return new DerSequence(tbsCertList, sigAlgID, sig);
		}
	}
}
